Second primary malignancy risk in thyroid cancer survivors: a systematic review and meta-analysis

The effect of thyroid cancer on the survival of patients with digestive system tumors using SEER database

The number of cancer survivors worldwide is increasing every year, making secondary primary cancers (SPC) is a growing health threat. Studies have been conducted to investigate the risk of occurrence between digestive system tumors (DST) and thyroid cancer (TC). However, existing studies have tended to focus more on the risk of developing SPC and less on the impact of SPC on the survival of cancer survivors. In this study, using the Surveillance, Epidemiology, and End Results database, we aimed to explore the impact of TC on the survival of patients with DST by data between 2000 and 2018. The study employed the standardized incidence ratio to assess the relative risk of SPC, propensity score matching was conducted to mitigate confounding effects, Kaplan-Meier, Cox proportional risk model and competitive risk model were used to analyze the factors affecting the overall survival and cancer-specific survival. We furthermore explored the influence of pathological types and radiotherapy of TC on the survival of DST patients. 518,901 patients with DST only, 801 patients with TC occurring earlier than DST (TC-1st), and 744 patients with DST occurring earlier than TC (DST-1st) were included. The total incidence rate of small intestine cancer after TC was higher than that of the general population, and the incidence of TC after DST was higher than in the general population. DST patients with a history of TC had better overall survival and lower cancer-specific mortality and this difference was particularly significant in patients with DST-1st. In addition, radiotherapy for TC had no effect on cancer-specific mortality in patients with DST.

The Prognostic Impact of Radioiodine Therapy in Patients with Papillary Thyroid Cancer

Radioiodine (RAI) therapy after surgery, is an important component for the treatment of patients with papillary thyroid cancer (PTC), the most common thyroid cancer. In this study we sought to evaluate the cancer-specific survival (CSS) impact of RAI in specific thyroid cancer subgroups. The Surveillance, Epidemiology, and End Results (SEER) database were used to identify patients with PTC who underwent surgery between 2000 and 2019. Patients not treated with RAI were compared to those treated with RAI using propensity score matching (PSM) on the basis of identical inclusion criteria. A total of 106 333 patients were identified from the SEER database. RAI therapy was associated with improved CSS in the matched cohort (HR: 0.83; 95% CI: 0.72-0.96, p=0.01) but not in the unmatched data set (HR: 1.46; 95% CI: 1.30-1.64, p<0.001) among all PTC patients regardless of disease stage. Detailed analyses, however, showed that only patients with high-risk disease (pT3N1, pT4N1) experienced the greatest benefit in CSS. In the lower disease stages, no significant differences were recognized in the group of PTC patients with or without RAI therapy. One exception: in the group of PTC patients in stage pT1bN0, a significant difference was seen towards RAI. This is, however, most likely due to the large number of patients investigated. In summary, RAI therapy should not be used in low-risk PTC patients and might be used to some extent in intermediate-risk PTC patients. The histological suptype of the tumor needs to be considered in this context.

Thyroid Cancer Survivorship: Challenges and Opportunities

OBJECTIVE

To provide a narrative review of challenges and opportunities in the care of thyroid cancer survivors.

METHODS

A literature search for full-text articles pertaining to quality of life and survivorship in thyroid cancer was performed and supplemented with personal experience of the authors.

RESULTS

Despite usually favorable prognosis for most thyroid cancer survivors, health-related quality of life (HRQOL) can be as poor or even worse than that in more aggressive cancers. Worry of cancer recurrence and long-term effects from cancer treatment adversely affects HRQOL in addition to other factors. Disparities and financial hardships among thyroid cancer survivors further affect HRQOL. In addition to monitoring for cancer recurrence and managing hypothyroidism, long-term effects from cancer treatment, including surgical complications, effects from radioactive iodine therapy, a small but increased risk of second primary malignancies, and aging-related health conditions (bone, cardiac, and fertility), need to be monitored for and addressed during survivorship care.

CONCLUSION

Survivorship care models can vary depending on the specifics of the population served; however, a team-based survivor-centered approach provides the best care to thyroid cancer survivors.

Survival Outcomes in Thyroid Cancer Patients with Co-Occurring Breast Cancer: Evidence of Mortality Risk Attenuation

BACKGROUND

Previous studies have reported a strong correlation between breast cancer (BC) and thyroid cancer (TC) incidence. However, the clinical and oncological impact of these associations are not yet fully understood. Here, we aimed to explore the differences in clinicopathological characteristics between TC patients with and without BC, and the effect of a history of positive BC on TC survival.

METHODS

We retrospectively compared the clinical characteristics and survival rates of patients with TC alone and those with TC and BC in a primary cohort at our institution and in a second cohort using the Surveillance, Epidemiology, and End Results (SEER) database.

RESULTS

In our institutional cohort, survival rates were similar between patients with TC alone and those with TC-associated BC. However, using SEER data, we found that BC had a protective effect on TC patients and was associated with reduced TC mortality rates (hazard ratio [HR] = 0.72, 95% confidence interval [CI] 0.57 to 0.92; P = .026). After stratifying the TC patients according to co-occurring BC subtypes, we observed that higher survival rates were restricted to patients with coexisting luminal A BC (P = .015), which exhibit positive hormone receptors and do not express HER-2.

CONCLUSION

These findings suggest that hormone pathways may play a role in the co-occurrence of thyroid and breast cancers. Patients with TC coexisting with luminal A BC have higher survival rates. However, further studies on the mechanisms underlying the association between BC and TC are warranted.

Risk of Lymphoma and Leukemia in Thyroid Cancer Patients: A Retrospective Cohort Study in Germany

Thyroid cancer is the ninth most common cancer worldwide. While differentiated thyroid cancer (DTC) has a high survival rate, concerns arise regarding optimal treatment strategies and potential long-term risks, including second primary malignancies (SPMs), associated with therapies such as radioiodine (RAI). The aim of the present study was to investigate the association between thyroid cancer and the incidence of subsequent lymphoma and leukemia in Germany. This retrospective cohort study used the IQVIA TM Disease Analyzer database and included adults with a first documented diagnosis of thyroid cancer between January 2005 and December 2021 as well as propensity score matched individuals without thyroid cancer in 1284 general practices. Univariate Cox regression models were performed to examine the association between thyroid cancer and the incidence of subsequent lymphoma and leukemia. A total of 4232 thyroid cancer patients (mean age: 54.2 years; 73.6% female) and 21 160 controls (mean age: 54.2 years; 72.6% female) were available for analyses. Thyroid cancer was significantly associated with a higher lymphoma incidence (HR: 3.35, 95% CI: 2.04-5.52), especially in men (HR: 5.37) and those aged 61-70 years. Leukemia incidence was not significantly associated with thyroid cancer (HR: 1.79, 95% CI: 0.91-3.53), although associations were notable in younger age groups. Thyroid cancer is positively associated with a risk of subsequent lymphoma, highlighting the need for vigilant surveillance and tailored treatment strategies. While the association with leukemia is less pronounced, close surveillance remains critical, especially in younger patients.

Association Between a History of Breast Cancer and Decreased Thyroid Cancer-specific Mortality

CONTEXT

The clinical relevance of the well-known association between thyroid cancer (TC) and breast cancer (BC) remains to be further defined.

OBJECTIVE

This work aimed to investigate the effect of history of BC on the prognosis of TC.

METHODS

This was a comparative cohort study of tumor behaviors and TC-specific mortality in 5598 patients with papillary thyroid cancer (PTC) and 604 patients with follicular thyroid cancer (FTC), all with a history of BC (TC-BC patients), and their propensity score-matched TC patients without a history of BC (TCnoBC patients) in Surveillance, Epidemiology and End Results (SEER) 18. The main outcome measure was TC-specific mortality.

RESULTS

Lower TC distant metastasis rates of 2.4% vs 3.0% in PTC and 6.1% vs 9.1% in FTC and TC-specific mortality rates of 1.3% vs 2.6% in PTC and 5.8% vs 8.4% in FTC were found in TC-BC patients vs matched TCnoBC patients (all P < .05). Comparing TC-BC patients with matched TCnoBC patients, hazard ratios (HRs) for mortality were 0.472 (95% CI, 0.370-0.601) in PTC and 0.656 (95% CI, 0.461-0.934) in FTC (all P < .05). Such HRs for mortality in PTC were 0.397 (95% CI, 0.268-0.588; P < .001) when TC occurred before BC vs 0.607 (95% CI, 0.445-0.827; P = .002) when BC occurred before TC.

CONCLUSION

This study demonstrates a robust protective effect of a history of BC on TC-specific patient survival, which has strong implications for more precise prognostication of TC in such patients.

Risk of Subsequent Primary Cancers in Thyroid Cancer Survivors according to the Dose of Levothyroxine: A Nationwide Cohort Study

BACKGRUOUND

Current research has not investigated the effect of thyroid-stimulating hormone suppression therapy with levothyroxine on the risk for developing subsequent primary cancers (SPCs). This study aimed to investigate the association between levothyroxine dosage and the risk for SPCs in thyroid cancer patients.

METHODS

We conducted a nationwide population-based retrospective cohort study form Korean National Health Insurance database. This cohort included 342,920 thyroid cancer patients between 2004 and 2018. Patients were divided into the non-levothyroxine and the levothyroxine groups, the latter consisting of four dosage subgroups according to quartiles. Cox proportional hazard models were performed to evaluate the risk for SPCs by adjusting for variables including cumulative doses of radioactive iodine (RAI) therapy.

RESULTS

A total of 17,410 SPC cases were observed over a median 7.3 years of follow-up. The high-dose levothyroxine subgroups (Q3 and Q4) had a higher risk for SPC (adjusted hazard ratio [HR], 1.14 and 1.27; 95% confidence interval [CI], 1.05-1.24 and 1.17- 1.37; respectively) compared to the non-levothyroxine group. In particular, the adjusted HR of stomach (1.31), colorectal (1.60), liver and biliary tract (1.95), and pancreatic (2.48) cancers were increased in the Q4 subgroup. We consistently observed a positive association between high levothyroxine dosage per body weight and risk of SPCs, even after adjusting for various confounding variables. Moreover, similar results were identified in the stratified analyses according to thyroidectomy type and RAI therapy, as well as in a subgroup analysis of patients with good adherence.

CONCLUSION

High-dose levothyroxine use was associated with increased risk of SPCs among thyroid cancer patients regardless of RAI therapy.

Development and Validation of a Nomogram for Prognosis Prediction in Patients with Synchronous Primary Thyroid and Breast Cancer Based on SEER Database

This study aimed to develop prognostic prediction models for patients diagnosed with synchronous thyroid and breast cancer (TBC). Utilizing the SEER database, key predictive factors were identified, including T stage of thyroid cancer, T stage of breast cancer, M stage of breast cancer, patient age, thyroid cancer surgery type, and isotope therapy. A nomogram predicting 5-year and 10-year survival rates was constructed and validated, exhibiting strong performance (C-statistic: 0.79 in the development cohort (95% CI: 0.74-0.84), and 0.82 in the validation cohort (95% CI: 0.77-0.89)). The area under the Receiver Operator Characteristic (ROC) curve ranged from 0.798 to 0.883 for both cohorts. Calibration and decision curve analyses further affirmed the model's clinical utility. Stratifying patients into high-risk and low-risk groups using the nomogram revealed significant differences in survival rates (P < 0.0001). The successful development and validation of this nomogram for predicting 5-year and 10-year survival rates in patients with synchronous TBC hold promise for similar patient populations, contributing significantly to cancer research.

All-Cause and Cause-Specific Mortality Among Low-Risk Differentiated Thyroid Cancer Survivors in the United States

Background: Despite the excellent disease-specific survival associated with low-risk differentiated thyroid cancer (DTC), its diagnosis and management have been linked to patient concerns about cancer recurrence, treatment-related health risks, and mortality. Lack of information regarding long-term health outcomes can perpetuate these concerns. Therefore, we assessed all-cause and cause-specific mortality in a large cohort of individuals diagnosed with low-risk DTC. Methods: From the U.S. Surveillance, Epidemiology, and End Results-12 cancer registry database (1992-2019), we identified 51,854 individuals (81.8% female) diagnosed with first primary DTC at low risk of recurrence (≤4 cm, localized). We estimated cause-specific cumulative mortality by time since diagnosis, accounting for competing risks. Standardized mortality ratios (SMRs) and CIs were used to compare observed mortality rates in DTC patients with expected rates in the matched U.S. general population, overall and by time since DTC diagnosis. We used Cox proportional hazards models to examine associations between radioactive iodine (RAI) treatment and cause-specific mortality. Results: During follow-up (median = 8.8, range 0-28 years), 3467 (6.7%) deaths were recorded. Thyroid cancer accounted for only 4.3% of deaths (n = 148). The most common causes of death were malignancies (other than thyroid cancer) (n = 1031, 29.7%) and cardiovascular disease (CVD; n = 912, 26.3%). The 20-year cumulative mortality rate from thyroid cancer, malignancies (other than thyroid or nonmelanoma skin cancer), and CVD was 0.6%, 4.6%, and 3.9%, respectively. Lower than expected mortality was observed for all causes excluding thyroid cancer (SMR = 0.69 [CI 0.67-0.71]) and most specific causes, including all malignancies combined (other than thyroid cancer; SMR = 0.80 [CI 0.75-0.85]) and CVD (SMR = 0.64 [CI 0.60-0.69]). However, mortality rates were elevated for specific cancers, including pancreas (SMR = 1.58 [CI 1.18-2.06]), kidney and renal pelvis (SMR = 1.85 [CI 1.10-2.93]), and brain and other nervous system (SMR = 1.62 [CI 0.99-2.51]), and myeloma (SMR = 2.35 [CI 1.46-3.60]) and leukemia (SMR = 1.62 [CI 1.07-2.36]); these associations were stronger ≥10 years after diagnosis. RAI was not associated with risk of cause-specific death, but numbers of events were small and the range of administered activities was likely narrow. Conclusions: Overall, our findings provide reassurance regarding low overall and cause-specific mortality rates in individuals with low-risk DTC. Additional research is necessary to confirm and understand the increased mortality from certain subsequent cancers.

Causal relationship between prostate cancer and 12 types of cancers: multivariable and bidirectional Mendelian randomization analyses

BACKGROUND

Previous observational studies have shown an association between certain cancers and the subsequent risk of prostate cancer (PCa). However, the causal relationship between these cancers and PCa is still unclear. This study aimed to investigate the causal relationship between 12 common cancers and the risk of PCa.

METHODS

We employed genome-wide association studies (GWAS) to perform forward and reverse Mendelian randomization (MR) within two-sample frameworks. Furthermore, we conducted multivariable MR analyses to investigate the relationships between different types of cancer. In addition, multiple sensitivity analysis methods were employed to assess the robustness of our findings.

RESULTS

Our univariable MR analysis showed that genetically predicted hematological cancer was associated with a reduced risk of PCa (OR: 0.911, 95% CI 0.89-0.922, P = 0.03). Furthermore, MR analysis demonstrates that genetically predicted occurrence of thyroid gland and endocrine gland cancer also raised the risk of PCa (all P < 0.05). Multivariable analysis showed that thyroid gland cancer exhibited a higher incidence of PCa (OR: 1.12, 95% CI: 1.08-1.16, P = 0.008). In the reverse MR analysis, we found no significant inverse causal associations between PCa and 12 types of cancers.

CONCLUSION

In summary, this study provided insights into the causal relationships between various types of cancer and PCa. Hematological cancer was suggested to associate with a lower risk of PCa, while thyroid gland cancer and endocrine gland cancer might increase the risk. These findings contribute to the understanding of genetic factors related to PCa and its potential associations with other cancers.

Unbalanced bidirectional causal association between thyroid cancer and ER-positive breast cancer: should we recommend screening for thyroid cancer in breast cancer patients?

BACKGROUND

The association between breast cancer (BC) and thyroid cancer (TC) has been studied in several epidemiological studies. However, the underlying causal relationship between them is not yet clear.

METHODS

The data from the latest large-sample genome-wide association studies (GWAS) of BC and TC were searched in the public GWAS database. The BC GWAS data included estrogen receptor (ER)-positive and negative subgroups. Two-way two-sample Mendelian Randomization (MR) was used to explore the potential causal relationship between BC and TC. Inverse variance weighting (IVW) and the MR-Egger method were used to combine the estimation of each single nucleotide variation (previous single nucleotide polymorphism). BC was taken as the result, and the effect of TC exposure was analyzed. Then, the effect of BC exposure on the result of TC was analyzed.

RESULTS

Both IVW and MR-Egger results indicated that gene-driven thyroid cancer does not cause estrogen receptor-positive breast cancer and is a protective factor (β = -1.203, SE = 4.663*10-4, P = 0.010). However, gene-driven estrogen receptor-positive breast cancer can lead to the development of thyroid cancer (β = 0.516, SE = 0.220, P = 0.019).

CONCLUSION

From the perspective of gene drive, people with TC are less likely to have ER-positive BC. In contrast, people with ER-positive BC are more likely to have TC. Therefore, it is recommended that patients with BC be screened regularly for TC.

Impact of thyroid hormone replacement on the risk of second cancer after thyroidectomy: a Korean National Cohort Study

We aimed to investigate the effect of thyroid hormone administration on the risk of second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer. Data were extracted from the medical billing data of the Health Insurance Review and Assessment Service in South Korea. Patients between 19 and 80 years old who underwent thyroid surgery at least once between January 2009 and June 2020 were included. Data of patients with second primary cancer and control patients with matched age, sex, operation date, and follow-up duration were extracted at a ratio of 1:4. A nested case-control analysis was performed to exclude length bias to confirm the correlation between the duration of thyroid hormone administration, dose, and incidence of second primary cancer. Of the 261,598 patients who underwent surgery for thyroid cancer included in the study, 11,790 with second primary cancer and 47,160 without second primary cancer were matched. The average dose of thyroid hormone increased the adjusted odds ratio (OR) for both low (≤ 50 μg, OR 1.29, confidence interval (CI) 1.12-1.48) and high (< 100 μg, OR 1.24, CI 1.12-1.37) doses. Analyzing over time, the adjusted OR of second primary cancer increased, especially in short (≤ 1 year) (OR 1.19; CI 1.06-1.34) and long (> 5 years) duration (OR 1.25; CI 1.10-1.41). In conclusion, insufficient and excessive thyroid hormone replacement might be linked to increased second primary cancer in patients who underwent thyroidectomy for differentiated thyroid cancer.

Causal associations between thyroid cancer and IgA nephropathy: a Mendelian randomization study

BACKGROUND

The incidence of kidney disease caused by thyroid cancer is rising worldwide. Observational studies cannot recognize whether thyroid cancer is independently associated with kidney disease. We performed the Mendelian randomization (MR) approach to genetically investigate the causality of thyroid cancer on immunoglobulin A nephropathy (IgAN).

METHODS AND RESULTS

We explored the causal effect of thyroid cancer on IgAN by MR analysis. Fifty-two genetic loci and single nucleotide polymorphisms were related to thyroid cancer. The primary approach in this MR analysis was the inverse variance weighted (IVW) method, and MR‒Egger was the secondary method. Weighted mode and penalized weighted median were used to analyze the sensitivity. In this study, the random-effect IVW models showed the causal impact of genetically predicted thyroid cancer across the IgAN risk (OR, 1.191; 95% CI, 1.131-1.253, P < 0.001). Similar results were also obtained in the weighted mode method (OR, 1.048; 95% CI, 0.980-1.120, P = 0.179) and penalized weighted median (OR, 1.185; 95% CI, 1.110-1.264, P < 0.001). However, the MR‒Egger method revealed that thyroid cancer decreased the risk of IgAN, but this difference was not significant (OR, 0.948; 95% CI, 0.855-1.051, P = 0.316). The leave-one-out sensitivity analysis did not reveal the driving influence of any individual SNP on the association between thyroid cancer and IgAN.

CONCLUSION

The IVW model indicated a significant causality of thyroid cancer with IgAN. However, MR‒Egger had a point estimation in the opposite direction. According to the MR principle, the evidence of this study did not support a stable significant causal association between thyroid cancer and IgAN. The results still need to be confirmed by future studies.

Normal organ dosimetry for thyroid cancer patients treated with radioiodine as part of the multi-centre multi-national Horizon 2020 MEDIRAD project

PURPOSE

Dosimetry is rarely performed for the treatment of differentiated thyroid cancer patients with Na[131I]I (radioiodine), and information regarding absorbed doses delivered is limited. Collection of dosimetry data in a multi-centre setting requires standardised quantitative imaging and dosimetry. A multi-national, multi-centre clinical study was performed to assess absorbed doses delivered to normal organs for differentiated thyroid cancer patients treated with Na[131I]I.

METHODS

Patients were enrolled in four centres and administered fixed activities of 1.1 or 3.7 GBq of Na[131I]I using rhTSH stimulation or under thyroid hormone withdrawal according to local protocols. Patients were imaged using SPECT(/CT) at variable imaging time-points following standardised acquisition and reconstruction protocols. Whole-body retention data were collected. Dosimetry for normal organs was performed at two dosimetry centres and results collated.

RESULTS

One hundred and five patients were recruited. Median absorbed doses per unit administered activity of 0.44, 0.14, 0.05 and 0.16 mGy/MBq were determined for the salivary glands of patients treated at centre 1, 2, 3 and 4, respectively. Median whole-body absorbed doses for 1.1 and 3.7 GBq were 0.05 Gy and 0.16 Gy, respectively. Median whole-body absorbed doses per unit administered activity of 0.04, 0.05, 0.04 and 0.04 mGy/MBq were calculated for centre 1, 2, 3 and 4, respectively.

CONCLUSIONS

A wide range of normal organ doses were observed for differentiated thyroid cancer patients treated with Na[131I]I, highlighting the necessity for individualised dosimetry. The results show that data may be collated from multiple centres if minimum standards for the acquisition and dosimetry protocols can be achieved.

Second Primary Cancer Among Patients With Papillary Thyroid Carcinoma Following the Chernobyl Disaster

Importance

To our knowledge, there are no complete population-based studies of the risks of developing second malignant tumors after papillary thyroid carcinoma (PTC) in patients following the Chernobyl nuclear accident.

Objective

To study the risk of second primary cancers in patients with PTC after the Chernobyl disaster.

Design, Setting, and Participants

This was a retrospective cohort study conducted in the Republic of Belarus over a 31-year time frame evaluating patients with primary PTC and second malignant tumors. Personal data from the Belarussian Cancer Registry were used in the investigation, and only second primary cancers were included in the analysis. Patients were observed from January 1, 1990, to December 31, 2021, for the establishment of second primary malignant tumors.

Main Outcomes and Measures

For analysis, synchronous and metachronous tumors were grouped into 1 group (second primary cancer group). If the patient had more than 2 cancers, they were observed until development of a second tumor and, subsequently, the development of a third tumor. The starting point for calculating the number of person-years was the date of thyroid cancer diagnosis. The end point for calculating the number of person-years was the date of diagnosis of the second primary malignant tumor, the date of death, the date of the last visit of the patient, or December 31, 2021 (the end the of study period). The incidence of a second primary malignant tumor with PTC was calculated for the study groups using standardized incidence ratios.

Results

Of the 30 568 patients with a primary PTC included in this study, 2820 (9.2%) developed a second malignant tumor (2204 women and 616 men); the mean (SD) age of all patients at time of the primary cancer was 53.9 (12.6) years and at time of the secondary cancer was 61.5 (11.8) years. Overall, the standardized incidence ratio was statistically significant for all types of cancer (1.25; 95% CI, 1.21-1.30), including solid malignant tumors (1.20; 95% CI, 1.15-1.25) and all leukemias (1.61; 95% CI, 2.17-2.13). Cancers of the digestive system (466 cases [21.1%]), genital organs (376 cases [17.1%]), and breasts (603 cases [27.4%]) were the most prevalent second primary tumors in women following PTC. Second primary tumors of the gastrointestinal tract (146 cases [27.7%]), genitourinary system (139 cases [22.6%]), and urinary tract (139 cases [22.6%]) were the most prevalent in men. Urinary tract cancers (307 cases [10.9%]) and gastrointestinal tumors (612 cases [21.4%]) were the most prevalent second primary tumors overall.

Conclusions and Relevance

This cohort study reports the increased incidence of solid secondary tumors in men and women over a 31-year time frame after the Chernobyl disaster. Moreover, there was a statistically significant increased risk of second tumors of the breast, colon, rectum, mesothelium, eye, adnexa, meninges, and adrenal glands as well as Kaposi sarcoma. These data might have an effect on the follow-up of this cohort of patients to detect secondary malignant tumors at an early stage.

Initial results of the INSPIRE clinical trial-investigating radiation dosimetry for differentiated thyroid cancer patients

Introduction

The optimal strategy for differentiated thyroid cancer (DTC) patients treated with radioiodine (RAI) following thyroidectomy remains controversial. Multi-centre clinical studies are essential to identify strategies to improve patient outcomes while minimising treatment-induced toxicity.

Materials and Methods

The INSPIRE clinical trial (ClinicalTrials.gov Identifier: NCT04391244) aims to investigate patient-specific dosimetry for DTC patients and to determine the range of absorbed doses delivered to target and non-target tissues and their relationship with treatment outcome and toxicity.

Results

We report here initial results of the first 30 patients enrolled onto the INSPIRE trial. A large range of absorbed doses are observed for both thyroid remnants and salivary glands, with median values of 4.8 Gy (Range 0.2 - 242 Gy) and 0.3 Gy (Range 0.1 to 1.7 Gy), respectively.

Discussion

The preliminary study results are encouraging and could help to improve our understanding of absorbed doses to thyroid remnants and normal organs following RAI therapy. Such knowledge could potentially enable patient-specific treatment planning with improved clinical outcomes and quality-of-life of patients.

Risk of second primary lung cancer in patients with thyroid cancer: a meta-analysis based on big population studies

BACKGROUND

Previous studies have revealed that the number of cancer survivors developing a second primary malignancy is increasing, especially among thyroid cancer patients, and lung cancer is still the main cause of cancer death. Therefore, we aimed to investigate the risk of second primary lung cancer (SPLC) in patients with thyroid cancer.

METHODS

We searched the PubMed, Web of Science, Embase, and Scopus databases up to November 24, 2021, for relevant research and merged the standardized incidence ratios (SIRs) and 95% confidence intervals (95% CIs) to evaluate the risk of developing SPLC in patients with thyroid cancer.

RESULTS

Fourteen studies involving 1480,816 cases were included in our meta-analysis. The pooled result demonstrated that thyroid cancer patients may have a higher risk of SPLC than the general population (SIR = 1.21, 95% CI: 1.07-1.36, P < 0.01, I2 = 81%, P < 0.01). Subgroup analysis stratified by sex indicated that female patients may have a markedly higher risk of SPLC than male patients (SIR = 1.65, 95% CI: 1.40-1.94, P < 0.01, I2 = 75%, P < 0.01).

CONCLUSIONS

Thyroid cancer patients are more likely to develop SPLC than the general population, especially women. However, other risk factors must be investigated, and more prospective studies are needed to confirm our results.Registration: International Prospective Register of Systematic Reviews: No. CRD42021285399.

Chromatin-Accessible miRNA Regulons Driving Thyroid Tumorigenesis and Progression

BACKGROUND

Although papillary thyroid cancer can remain indolent, associated lymph node metastases and recurrence rates are approximately 50% and 20%, respectively. Omics-based medicine has led to the discovery of predictive biomarkers that can be used to predict tumor progression and clinical outcomes. We aimed to develop a noninvasive omics-driven blood test to allow accurate risk stratification and help tailor individual patient treatment plans.

STUDY DESIGN

RNA sequencing (seq) and microRNA analysis of The Cancer Genome Atlas and Gene Expression Omnibus datasets were employed to identify an epigenetic prognostic panel. Integrated bulk assay for transposase-accessible chromatin-seq and RNA-seq experiments confirmed the results. Sixty-two paired tumor and adjacent control thyroid tissues and 67 blood samples (62 papillary thyroid cancer and 5 controls) were analyzed for validation using sequencing and real-time polymerase chain reaction and correlated to clinical outcomes. A liposome-exosome fusion clustered regularly interspaced short palindromic repeats (CRISPR)-fluorescent detection system miRNA assay was developed. A predictive risk nomogram was generated and tested for performance.

RESULTS

Our miRNA panel (miR-146b-5p and miR-221-3p) from tissue and blood was associated with aggressive features and was located within accessible chromatin regions. The miRNA risk score and prognostic nomogram showed higher accuracy in predicting lymph node metastases (miR-146b: area under the curve [AUC] 0.816, sensitivity 76.9%; miR-221: AUC 0.740, sensitivity 79.5%) and recurrence (miR-146b: AUC 0.921, sensitivity 75.0%; miR-221: AUC 0.756, sensitivity 70.0%; p < 0.001) than staging and American Thyroid Association risk stratification. CRISPR-based miRNA assays showed upregulation in the blood of cancer cohorts.

CONCLUSIONS

CRISPR-based detection of miR-146b and miR-221 in the blood of thyroid cancer patients is a reliable and noninvasive tool for real-time assessment and prognostication that has great potential to provide a direct impact on the care of these patients.

Impact of thyroid cancer on the cancer risk in patients with non-alcoholic fatty liver disease or dyslipidemia

The raised prevalence of obesity has increased the incidence of obesity-related metabolic diseases such as dyslipidemia (DL) and non-alcoholic fatty liver disease (NAFLD), along with the development and progression of various types of cancer, including thyroid cancer. In this study, we investigated whether thyroid cancer in patients with DL and NAFLD could be a risk factor for other cancers. To achieve our goal, we generated two independent cohorts from our institution and from the National Health Insurance System in South Korea. Based on the ICD-10 code, we conducted exact matching (1:5 matching) and estimated the overall risk of thyroid cancer for other cancers in patients with DL or NAFLD. Univariate and multivariate analyses showed that the hazard ratio (HR) of thyroid cancer was 2.007 (95% Confidence Interval [CI], 1.597-2.522) and 2.092 (95% CI, 1.546-2.829), respectively in the institutional cohort and 1.329 (95% CI, 1.153-1.533) and 1.301 (95% CI, 1.115-1.517), respectively in the nationwide cohort. Risk analysis revealed a significant increase in the HR in lip, tongue, mouth, lung, bone, joint, soft tissue, skin, brain, male cancers and lymphoma after thyroid cancer occurred. Thyroid cancer in patients with DL or NAFLD might be a valuable factor for predicting the development of other cancers.

Breast cancer risk among thyroid cancer survivors and the role of I-131 treatment

BACKGROUND

Female thyroid cancer survivors are more likely to have a higher risk of breast cancer compared to the general population, and the underlying causes are yet to be understood. The potential role of I-131 treatment on this association remains controversial.

METHODS

We pooled individual data of women who were treated for differentiated thyroid cancer from 1934 to 2005 in France, Italy and Sweden. Standardized incidence ratios (SIRs) for breast cancer were estimated by comparison with age, sex and calendar-year expected values of the general population in each country. We estimated breast cancer risk in relation to I-131 treatment using time-dependent Poisson models.

RESULTS

Of 8475 women (mean age at diagnosis: 45 years, range 2-90 years), 335 were diagnosed with breast cancer [SIR = 1.52, 95% confidence interval (CI): 1.36-1.69] during a median follow-up time of 12.7 years since diagnosis. Overall, breast cancer risk did not differ between women treated or not with I-131 (relative risk=1.07, 95% CI 0.84-1.35). However, breast cancer risk increased with increasing cumulative I-131 activity, without significant departure from linearity (excess relative risk per 100 mCi=17%, 95% CI: 2% to 38%). The higher risk associated with a cumulative I-131 activity of ≥100 mCi and ≥400 mCi was translated into 4 (95% CI -4 to 13) and 42 (95% CI -8 to 93) excess breast cancer cases per 10,000 person-years, respectively.

CONCLUSIONS

An elevated risk was observed for the highest cumulative administered activity (>=400 mCi), and a significant dose-dependent association was observed among thyroid cancer survivors who were treated with I-131. However, overall, I-131 treatment might only explain partly the increase in breast cancer risk among female thyroid cancer survivors.

The co-occurrence of both breast- and differentiated thyroid cancer: incidence, association and clinical implications for daily practice

Background

Breast cancer (BC) and differentiated thyroid cancer (TC) are two common cancer types with the highest incidence in women. BC and TC can develop synchronous or metachronous and the occurrence of both is higher than expected by chance. This study aimed to examine the association between BC and TC in the Netherlands.

Methods

This is a retrospective cohort study during the period of 1989–2020 retrieved from the Netherlands Cancer Registry (NCR). Patients diagnosed with BC-TC and BC alone as control group and TC-BC and TC alone as control group were included. The primary outcome was the standardized incidence ratio (SIR) of BC-TC and TC-BC. Secondary outcomes included data on the demographics, type of malignancy, treatment and overall survival (OS).

Results

The incidence of TC among 318.002 women with BC (BC-TC) was 0.1% (423 patients) (SIR = 1.86 (95% CI: 1.40–2.32)) and the incidence of BC among 12,370 patients with TC (TC-BC) was 2.9% (355 patients) (SIR = 1.46 (95% CI: 1.09–1.83)). BC-TC patients were younger compared to the BC alone group at BC diagnosis (55 vs 60 years, p < 0.001). The age-adjusted odds ratio to develop TC was not significantly increased for patients who received chemotherapy and radiotherapy. Most TC cases were synchronous tumors after BC diagnosis (19%) with a TNM stage 1. Only 6% of the BC tumors after TC occurred synchronous with a TNM stage 1 in most cases. The OS of all groups was the most favorable in patients with both BC and TC compared to BC- and TC alone.

Conclusion and relevance

The SIR of TC after BC diagnosis and BC after TC diagnosis was higher than predicted based on the rates of the general population. TC and BC as second primary tumors were diagnosed in an early stage and did not affect overall survival. Therefore, Dutch women who have been treated for BC or TC require no special surveillance for their thyroid- and breast gland.

A miRNA-Based Prognostic Model to Trace Thyroid Cancer Recurrence

Simple Summary

Some thyroid tumors elected for surveillance remain indolent, while others progress. The mechanism responsible for this difference is poorly understood, making it challenging to devise patient surveillance plans. Early prediction is important for tailoring treatment and follow-up in high-risk patients. The aim of our study was to identify predictive markers for progression. We leveraged a highly sensitive test that accurately predicts which thyroid nodules are more likely to develop lymph node metastasis, thereby improving care and outcomes for cancer patients.

Abstract

Papillary thyroid carcinomas (PTCs) account for most endocrine tumors; however, screening and diagnosing the recurrence of PTC remains a clinical challenge. Using microRNA sequencing (miR-seq) to explore miRNA expression profiles in PTC tissues and adjacent normal tissues, we aimed to determine which miRNAs may be associated with PTC recurrence and metastasis. Public databases such as TCGA and GEO were utilized for data sourcing and external validation, respectively, and miR-seq results were validated using quantitative real-time PCR (qRT-PCR). We found miR-145 to be significantly downregulated in tumor tissues and blood. Deregulation was significantly related to clinicopathological features of PTC patients including tumor size, lymph node metastasis, TNM stage, and recurrence. In silico data analysis showed that miR-145 can negatively regulate multiple genes in the TC signaling pathway and was associated with cell apoptosis, proliferation, stem cell differentiation, angiogenesis, and metastasis. Taken together, the current study suggests that miR-145 may be a biomarker for PTC recurrence. Further mechanistic studies are required to uncover its cellular roles in this regard.

Incidental discovery of a Hodgkin lymphoma synchronous to a papillary thyroid carcinoma

Papillary thyroid carcinoma is the most common type of thyroid cancer and accounts for almost 89.4% of all thyroid carcinomas. Hodgkin lymphoma is a heterogeneous group of neoplasms and represents 10% of lymphomas. These two cancers do not share the same risk factors. Some studies have reported the association of thyroid papillary carcinoma with lymphomas, mainly Hodgkin's lymphoma, treated with radiotherapy. However, to our knowledge less than 10 cases have illustrated synchronous papillary thyroid carcinoma and Hodgkin lymphoma with no history of radiotherapy. We present the case of a 49-year-old female patient, with no history of past exposure to radiation, who was incidentally diagnosed with Hodgkin lymphoma during the work up for papillary thyroid carcinoma. Our patient had total thyroïdectomy with cervical lymphadenectomy. The histopathologic examination concluded to a papillary thyroid carcinoma of classical variant. And the lymph node dissection enabled us to diagnose not only papillary thyroid carcinoma's lymph node metastasis, but also Hodgkin Lymphoma. This discovery of the Hodgkin lymphoma was totally incidental. The discovery of synchronous tumors in patients with papillary thyroid carcinoma has been reported in the literature. However, the diagnosis of Hodgkin through lymph node dissection for papillary thyroid carcinoma is extremely rare. This underlines the singularity and the importance of our case. The synchronous papillary thyroid carcinoma and Hodgkin lymphoma is a rare condition, which may pose significant diagnostic and treatment dilemmas. To date, there is no standardized approach due to lack of experience. The molecular mechanisms of this link are poorly understood and yet remain to be elucidated.

Second primary malignancies induced by radioactive iodine treatment of differentiated thyroid carcinoma - a critical review and evaluation of the existing evidence

PURPOSE

Concern is growing about long-term side effects of differentiated thyroid cancer treatment, most notably radioactive iodine (RAI) therapy. However, published studies on the subject have had heterogeneous cohorts and conflicting results. This review seeks to provide an updated evaluation of published evidence, and to elucidate the risk of second primary malignancies (SPMs), especially secondary hematologic malignancies (SHMs), attributable to RAI therapy.

METHODS

An extensive literature search was performed in Ovid MEDLINE, Ovid MEDLINE and In-Process & Other Non-Indexed Citations, Ovid MEDLINE Epub Ahead of Print, Cochrane Central Register of Controlled Trials (CENTRAL) and PubMed. Studies regarding RAI-induced SPMs or a dose-response relationship between RAI therapy and SPMs were identified, 10 of which were eligible for the analysis. We evaluated risk of bias in each study and judged quality of evidence (QOE) across all studies using the Grading of Recommendations, Assessment, Development and Evaluations approach.

RESULTS

For the outcome "SPM", the relative effect (relative risk, hazard ratio, or odds ratio) of RAI vs. no RAI ranged from 1.14 to 1.84 across studies, but most results were not statistically significant. For the outcome "SHM", reported relative effects ranged from 1.30 to 2.50, with 2/3 of the studies presenting statistically significant results. In 7/8 of the studies, increased risk for SPM was shown with increasing cumulative RAI activity. QOE was "very low" regarding SPM after RAI and regarding a dose-response relationship, and "low" for SHM after RAI.

CONCLUSION

Based on low quality evidence, an excess risk for the development of SPM cannot be excluded but is expected to be small.

Association between Thyroid Cancer and Breast Cancer: Two Longitudinal Follow-Up Studies Using a National Health Screening Cohort

Background: The purpose of this study was to evaluate the association between thyroid cancer and breast cancer. Methods: Data from the Korean National Health Insurance Service-Health Screening Cohort were collected from 2002 to 2013. In study I, 3949 thyroid cancer participants were 1:4 matched with 15,796 control I participants, and hazard ratios (HRs) with 95% confidence intervals (CIs) for breast cancer were evaluated using a stratified Cox proportional hazard model. In study II, 3308 breast cancer participants were 1:4 matched with 13,232 control II participants, and HRs with 95% CIs for thyroid cancer were assessed in the same way as in study I. In the subgroup analyses, associations were analyzed according to radioactive iodine (RAI) treatment and age (<60 years old and ≥60 years old). Results: The adjusted HR for breast cancer in the thyroid cancer group was 1.64 (95% CI = 1.13–2.39, p = 0.010). The adjusted HR for thyroid cancer in the breast cancer group was 1.91 (95% CI = 1.47–2.49, p < 0.001). In the subgroup analyses, the groups that were older and not treated with RAI treatment showed consistent results in study I, and the younger and older groups showed consistent results in study II. Conclusions: Based on this cohort study, breast and thyroid cancer have a reciprocal positive association.

Radioactive Iodine Treatment for Children and Young Adults with Thyroid Cancer in South Korea: A Population-based Study

PURPOSE

This study investigated radioactive iodine treatment (RAIT) patterns and the secondary cancer incidence among children and young adults receiving RAIT after thyroidectomy for thyroid cancer.

METHODS

This population-based cohort study used the Health Insurance Review and Assessment database of South Korea to identify a total of 18 617 children and young adults (0-29 years) who underwent thyroidectomy for thyroid cancer between 2008 and 2018. We recorded age at surgery, sex, the interval from surgery to RAIT, the doses of RAI, the number of RAIT sessions, and secondary cancer incidence.

RESULTS

A total of 9548 (51.3%) children and young adults underwent 1 or more RAIT sessions. The initial dose of RAIT was 4.35 ± 2.19 GBq. The overall RAIT frequency fell from 60.9% to 38.5%, and the frequency of high-dose RAIT (>3.7 GBq) fell from 64.2% to 36.5% during the observational period. A total of 124 cases of secondary cancer developed during 120 474 person-years of follow-up; 43 (0.5%) in the surgery cohort and 81 (0.8%) in the RAIT cohort. Thus, the RAIT cohort was at an increased risk of secondary cancer (adjusted hazard ratio 1.52 [95% confidence interval 1.03-2.24], P = 0.035).

CONCLUSION

The proportion of children and young adults receiving RAIT, and the RAI dose, fell significantly over the observational period. RAIT was associated with secondary cancers. This is of major concern in the context of child and young adult thyroid cancer survivors.

Risk and outcome of subsequent malignancies after radioactive iodine treatment in differentiated thyroid cancer patients

BACKGROUND

We identified differentiated thyroid cancer (DTC) survivors from SEER registries and performed Poisson regression to calculate the relative risks (RRs) of subsequent malignancies (SMs) by different sites associated with radioactive iodine (RAI) treatment, and the attributable risk proportion of RAI for developing different SMs.

RESULTS

We identified 4628 of 104,026 DTC patients developing a SM after two years of their DTC diagnosis, with a medium follow-up time of 113 months. The adjusted RRs of developing SM associated with RAI varied from 0.98 (0.58-1.65) for neurologic SMs to 1.37 (1.13-1.66) for hematologic SMs. The RRs of developing all cancer combined SMs generally increased with age at DTC diagnosis and decreased with the latency time. We estimated that the attributable risk proportion of RAI treatment is only 0.9% for all cancer combined SMs and 20% for hematologic SMs, which is the highest among all SMs. The tumor features and mortalities in patients treated with and without RAI are generally comparable.

CONCLUSION

With the large population based analyses, we concluded that a low percentage of DTC survivors would develop SMs during their follow-up. Although the adjusted RR of SMs development increased slightly in patients receiving RAI, the attributable risk proportion associated with RAI was low, suggesting the absolute number of SMs induced by RAI in DTC survivors would be low. The attributable risk proportion of RAI treatment is the highest in hematological SMs, but when in consideration of its low incidence among all DTC survivors, the absolute number of hematological SMs was low.

Increased expression of thyroid hormone receptor alpha and estrogen receptor alpha in breast cancer associated with thyroid cancer

INTRODUCTION

Breast cancer co-occurred with thyroid cancer might be associated with thyroid hormone receptor (TR) and estrogen receptor (ER), but few have been reported. We aimed to investigate the expression and prognostic significance of ERs and TRs in such settings.

MATERIAL AND METHODS

Tissue microarrays were constructed from 75 patients with breast and thyroid cancer (BC + TC) who were retrospectively recruited between 1999 and 2012 and 147 with breast cancer only (BC controls). The ERα, ERβ, TRα, and TRβ expression levels were analyzed by immunohistochemistry.

RESULTS

TRα expression was more frequently observed in the BC + TC group than the BC control group both in the normal (51.5% vs 23.3%, respectively, p = 0.009) and cancer tissues (21.6% vs 6.8%, respectively, p = 0.001). The BC + TC group showed greater ERα-positivity in the cancer tissues (79.7% vs 58.7%, respectively, p = 0.002) than the BC control group. The degree of ERα- and TRα-positivity was unchanged by radioactive treatment or serum thyroid stimulating hormone levels. In the BC + TC group, ERα-positivity was associated with earlier disease stage I/IIA (81.0% vs 50.0%; p = 0.031) and lower recurrence rates (8.5% vs 40.0%; p = 0.002). TRα-positivity alone was not associated with any recurrence-free survival-related differences, and ERα- and TRα-negativity were associated with significantly shorter recurrence-free survival (p < 0.001).

CONCLUSION

Enhanced ERα and TRα expression in breast cancer is associated with thyroid cancer occurrence, and the observed association with prognosis suggests the possible role of ERs and TRs in the link between breast cancer and thyroid cancer.

Impact of Dyslipidemia on the Risk of Second Cancer in Thyroid Cancer Patients: A Korean National Cohort Study

BACKGROUND

Studies have shown that radioactive iodine therapy (RAIT) affects the development of second cancer in thyroid cancer patients. The impact of other factors, such as dyslipidemia are not clear.

METHODS

A retrospective analysis of thyroid cancer patients with a 1,251,913 person-year follow-up was conducted using data from the Health Insurance Review and Assessment database in South Korea from January 2008 to December 2018. We investigated factors related to second cancer development using a nested case-control analysis to avoid length bias.

RESULTS

The overall risk of developing second cancer was higher in thyroid cancer patients than in the general population [standardized incidence ratio, 3.34; 95% confidence interval (CI) 3.30-3.39]. Second cancer incidence was higher in patients who received RAIT than in those who did not [odds ratio (OR) 1.130; 95% CI 1.094-1.169]. Moreover, the risk of second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.265; 95% CI 1.223-1.309). After adjustment for RAIT, the incidence of a second cancer was higher in patients with dyslipidemia than in those without dyslipidemia (OR 1.262; 95% CI 1.221-1.306).

CONCLUSIONS

The risk of second cancer development in patients with thyroid cancer appears to be high. Dyslipidemia may be associated with an increased risk of several types of second cancers.

Second primary malignancies in patients with papillary thyroid carcinoma after effect of post-chernobyl irradiation: A risk analysis of more than two decades of observations

BACKGROUND

Second primary malignancy in patients with papillary thyroid carcinoma after Chernobyl accident is an emerging problem. The aims of the study are to investigate the rates and distribution of second primary malignant tumours in Belarus survivors of post-Chernobyl papillary thyroid carcinoma and the cumulative rate of developing a second primary malignancy in a group of patients with metachronous second primaries.

METHODS

Patients aged 18 or younger at the time of Chernobyl accident who were diagnosed with papillary thyroid carcinoma after 1986 were identified from the Belarus Cancer Registry. The clinical and demographic of these patients were analysed to correlate with the factors for the development of secondary primary cancer.

RESULTS

Secondary primary cancer was detected in 1.8 % (119 of 6559) of the patients with papillary thyroid carcinoma. The cumulative incidence tended to rise with increasing age of the cohort and varied depending on the sex of patients. In female patients, breast carcinoma and genital tract carcinomas prevailed, in men patients - lymphoma/ leukaemia and the alimentary tract malignancies predominated. A significant excess risk was revealed for breast carcinoma in females, colon carcinoma in males, and the urinary system carcinomas in males (absolute excess risk [AER] = 3.23, 3.01 and 2.17 correspondingly). Overall, our results pointed to the increased risk of new solid primaries in females, males and both genders (AER = 3.31, 7.19, 4.28 correspondingly) as well as increase risk of lymphoid/hematopoietic malignancies in females and both genders (AER = 1.24) and leukaemia in male patients (AER = 1.45).

CONCLUSION

Patients with papillary thyroid carcinoma after Chernobyl accident are at risk of secondary primary malignancy. Awareness and screening of secondary cancer is needed for patients with papillary thyroid carcinoma after Chernobyl accident.

The Role of Nuclear Medicine in the Clinical Management of Benign Thyroid Disorders, Part 1: Hyperthyroidism

Benign thyroid disorders, especially hyper- and hypothyroidism, are the most prevalent endocrine disorders. The most common etiologies of hyperthyroidism are autoimmune hyperthyroidism (Graves disease, GD), toxic multinodular goiter (TMNG), and toxic thyroid adenoma (TA). Less common etiologies include destructive thyroiditis (e.g., amiodarone-induced thyroid dysfunction) and factitious hyperthyroidism. GD is caused by autoantibodies against the thyroid-stimulating hormone (TSH) receptor. TMNG and TA are caused by a somatic activating gain-of-function mutation. Typical laboratory findings in patients with hyperthyroidism are low TSH, elevated free-thyroxine and free-triiodothyronine levels, and TSH-receptor autoantibodies in patients with GD. Ultrasound imaging is used to determine the size and vascularity of the thyroid gland and the location, size, number, and characteristics of thyroid nodules. Combined with lab tests, these features constitute the first-line diagnostic approach to distinguishing different forms of hyperthyroidism. Thyroid scintigraphy with either radioiodine or ^99mTc-pertechnetate is useful to characterize different forms of hyperthyroidism and provides information for planning radioiodine therapy. There are specific scintigraphic patterns for GD, TMNG, TA, and destructive thyroiditis. Scintigraphy with ^99mTc-sestamibi allows differentiation of type 1 from type 2 amiodarone-induced hyperthyroidism. The radioiodine uptake test provides information for planning radioiodine therapy of hyperthyroidism. Hyperthyroidism can be treated with oral antithyroid drugs, surgical thyroidectomy, or ¹³¹I-iodide. Radioiodine therapy is generally considered after failure of treatment with antithyroid drugs, or when surgery is contraindicated or refused by the patient. In patients with TA or TMNG, the goal of radioiodine therapy is to achieve euthyroid status. In GD, the goal of radioiodine therapy is to induce hypothyroidism, a status that is readily treatable with oral thyroid hormone replacement therapy. Dosimetric estimates based on the thyroid volume to be treated and on radioiodine uptake should guide selection of the ¹³¹I-activity to be administered. Early side effects of radioiodine therapy (typically mild pain in the thyroid) can be handled by nonsteroidal antiinflammatory drugs. Delayed side effects after radioiodine therapy for hyperthyroidism are hypothyroidism and a minimal risk of radiation-induced malignancies.

Breast Cancer After Treatment of Differentiated Thyroid Cancer With Radioiodine in Young Females: What We Know and How to Investigate Open Questions. Review of the Literature and Results of a Multi-Registry Survey

Published studies on the risk of radiation-induced second primary malignancy (SPM) after radioiodine treatment (RAI) of differentiated thyroid cancer (DTC) refer mainly to patients treated as middle-aged or older adults and are not easily generalizable to those treated at a younger age. Here we review available literature on the risk of breast cancer as an SPM after RAI of DTC with a focus on females undergoing such treatment in childhood, adolescence, or young adulthood. Additionally, we report the results of a preliminary international survey of patient registries from academic tertiary referral centers specializing in pediatric DTC. The survey sought to evaluate the availability of sufficient patient data for a potential international multicenter observational case-control study of females with DTC given RAI at an early age. Our literature review identified a bi-directional association of DTC and breast cancer. The general breast cancer risk in adult DTC survivors is low, ~2%, slightly higher in females than in males, but presumably lower, not higher, in those diagnosed as children or adolescents than in those diagnosed at older ages. RAI presumably does not substantially influence breast cancer risk after DTC. However, data from patients given RAI at young ages are sparse and insufficient to make definitive conclusions regarding age dependence of the risk of breast cancer as a SPM after RAI of DTC. The preliminary analysis of data from 10 thyroid cancer registries worldwide, including altogether 6,449 patients given RAI for DTC and 1,116 controls, i.e., patients not given RAI, did not show a significant increase of breast cancer incidence after RAI. However, the numbers of cases and controls were insufficient to draw statistically reliable conclusions, and the proportion of those receiving RAI at the earliest ages was too low.In conclusion, a potential international multicenter study of female patients undergoing RAI of DTC as children, adolescents, or young adults, with a sufficient sample size, is feasible. However, breast cancer screening of a larger cohort of DTC patients is not unproblematic for ethical reasons, due to the likely, at most slightly, increased risk of breast cancer post-RAI and the expected ~10% false-positivity rate which potentially produced substantial "misdiagnosis."

Association Between Pregnancy Outcomes and Radioactive Iodine Treatment After Thyroidectomy Among Women With Thyroid Cancer

IMPORTANCE

Current guidelines recommend that women delay pregnancy for 6 to 12 months after the receipt of radioactive iodine treatment (RAIT) following thyroidectomy for differentiated thyroid carcinoma. Although concerns exist regarding the risks associated with pregnancy after RAIT, no large-scale study, to date, has investigated the association between RAIT and pregnancy outcomes.

OBJECTIVE

To investigate whether RAIT was associated with increases in adverse pregnancy outcomes among South Korean women who received RAIT after thyroidectomy for thyroid cancer and to evaluate the appropriate interval between RAIT and conception.

DESIGN, SETTING, AND PARTICIPANTS

This population-based cohort study used the Health Insurance Review and Assessment database of South Korea to identify a total of 111 459 women of childbearing age (20-49 years) who underwent thyroidectomy for the treatment of differentiated thyroid carcinoma between January 1, 2008, and December 31, 2015. Participants were allocated to 2 cohorts: those who underwent surgery alone (n = 59 483 [53.4%]) and those who underwent surgery followed by RAIT (n = 51 976 [46.6%]). The pregnancy outcomes data were collected from January 1, 2008, to December 31, 2017.

MAIN OUTCOMES AND MEASURES

The rates of abortion (both spontaneous and induced), preterm delivery, and congenital malformation were assessed. Multivariate logistic regression models were used to control for confounding variables.

RESULTS

Among the 111 459 women of childbearing age who underwent thyroidectomy with or without RAIT for the treatment of thyroid cancer, the mean (SD) age at surgery or RAIT was 39.8 (6.7) years. Of those, 10 842 women (9.7%) became pregnant, and the mean (SD) age at conception was 33.3 (4.4) years. The rates of abortion, preterm delivery, and congenital malformation among patients who underwent surgery alone compared with patients who underwent surgery followed by RAIT were 30.7% vs 32.1% for abortion, 12.8% vs 12.9% for preterm delivery, and 8.9% vs 9.0% for congenital malformation, respectively (P > .05). A subgroup analysis based on the interval between RAIT and conception indicated congenital malformation rates of 13.3% for the interval of 0 to 5 months, 7.9% for 6 to 11 months, 8.3% for 12 to 23 months, and 9.6% for 24 months or more. The adjusted odds ratio of congenital malformation was 1.74 (95% CI, 1.01-2.97; P = .04) in conceptions that occurred 0 to 5 months after RAIT compared with conceptions that occurred 12 to 23 months after RAIT. The abortion rates based on the interval between RAIT and conception were 60.6% for the interval of 0 to 5 months, 30.1% for 6 to 11 months, 27.4% for 12 to 23 months, and 31.9% for 24 months or more.

CONCLUSIONS AND RELEVANCE

These large-scale real-world data indicate that receipt of RAIT before pregnancy does not appear to be associated with increases in adverse pregnancy outcomes when conception occurs 6 months or more after treatment.

Decreased breast cancer-specific mortality risk in patients with a history of thyroid cancer

Previous studies have documented an intrinsic association between breast cancer (BC) and thyroid cancer (TC), but the clinical relevance of this relationship is not well defined. In the present study, we specifically investigated the impact of a history of TC on clinical outcomes of BC. We performed a population-based comparative analysis of tumor behaviors and BC-specific mortalities in 427,893 female patients with BC in the USA Surveillance, Epidemiology and End Results 9 database (1973–2013). In this cohort of subjects, 2,569 patients also had a history of differentiated TC (BC/TC), including BC diagnosed before TC (BC-1st) and BC diagnosed after TC (TC-1st), with the median follow-up time of 81 (IQR, 33–160) months. We found that, compared with matched BC-only patients, less aggressive BC tumor behaviors occurred in BC/TC patients, as exemplified by a distant metastasis rate of 7.0% in the former versus 3.3% in the latter (P<0.001). In BC/TC, BC-1st, and TC-1st patients versus their matched BC-only patients, BC-specific mortalities were 11.3% versus 21.0%, 9.9% versus 26.4%, and 12.4% versus 16.9%. These corresponded to hazard ratios (HR) (95% CI) of 0.47 (0.42–0.53), 0.31 (0.26–0.37), and 0.72 (0.61–0.84), respectively (all P<0.001), being lowest in BC-1st patients <50 years old [HR = 0.22 (0.16–0.31)], which remained significant after adjustment for clinicopathological and socioeconomic factors. Estrogen/progesterone receptor expression in BC tumors was significantly higher in patients with BC/TC than matched BC-only patients, providing evidence that BC in the former was biologically unique. Thus, a history of TC, particularly in younger BC-1st patients, may identify BC as a unique disease entity characterized by a decreased disease-specific mortality risk. The results have potentially important clinical and biological implications for BC in this special patient population and encourage further studies to confirm.

Initial treatment of pediatric differentiated thyroid cancer: a review of the current risk-adaptive approach

Differentiated thyroid cancer in children is a rare disease, accounting for only 1.4% of all pediatric malignancies. The diagnosis, biological behavior and treatment of differentiated thyroid cancer in children is different from that in adults. While there are many unresolved issues regarding approaches to management of differentiated thyroid cancer in the pediatric population, there is near universal consensus that treatment of this disease, which includes total thyroidectomy, central lymph node dissection at the time of initial surgery in those with nodal metastases, and the possible use of iodine-131 radiotherapy, is best performed by specialists including high-volume endocrine surgeons and experts with experience in calculating and administering radioactive iodine in children, when deemed appropriate.

Recombinant human thyrotropin (rhTSH) versus Levo-thyroxine withdrawal in radioiodine therapy of differentiated thyroid cancer patients: differences in abdominal absorbed dose

PURPOSE

In DTC patients, 131-radioiodine therapy has routinely been used for many years for thyroid remnant ablation after thyroid surgery. To date, two different strategies can be used to achieve sufficient TSH stimulation on thyroid remnant: (I) Levo-thyroxine withdrawal or (II) rhTSH stimulation. The aim of our study was to compare the abdominal absorbed dose ratio between differentiated thyroid cancer patients who underwent thyroid remnant ablation after either L-T4 withdrawal or rhTSH stimulation.

METHODS

We reviewed the records of 63 patients affected by differentiated thyroid cancer. All patients underwent thyroid remnant ablation after either L-T4 withdrawal or rhTSH stimulation. A post-therapy whole-body scan was obtained 5 days after 131-radioiodine therapy. Qualitative and quantitative image analysis was performed. Quantitative analysis was performed by drawing seven regions of interest on the abdomen (anterior and posterior views) to estimate both the activity ratio (AR) and absorbed dose ratio (DR) obtained in patients treated in hypothyroidism or after rhTSH stimulation.

RESULTS

The values of the activity and absorbed dose ratios obtained on each abdomen region (liver, stomach, ascending colon, transverse colon, descending colon, rectum, and small intestine) were always higher in patients treated after L-T4 withdrawal than after rhTSH stimulation with p-values of 0.000, 0.000, 0.001, 0.000, 0.022, 0.007, and 0.002, respectively.

CONCLUSIONS

DTC patients treated with 131-radioiodine after rhTSH stimulation have lower abdominal radioiodine activity than hypothyroid patients. Our data could be of practical relevance in terms of patient management. The potential impact on rare radioiodine-related gastrointestinal side effects is to be established in specifically designed prospective studies.

Long-Term Endocrine and Metabolic Consequences of Cancer Treatment: A Systematic Review

The number of patients surviving ≥5 years after initial cancer diagnosis has significantly increased during the last decades due to considerable improvements in the treatment of many cancer entities. A negative consequence of this is that the emergence of long-term sequelae and endocrine disorders account for a high proportion of these. These late effects can occur decades after cancer treatment and affect up to 50% of childhood cancer survivors. Multiple predisposing factors for endocrine late effects have been identified, including radiation, sex, and age at the time of diagnosis. A systematic literature search has been conducted using the PubMed database to offer a detailed overview of the spectrum of late endocrine disorders following oncological treatment. Most data are based on late effects of treatment in former childhood cancer patients for whom specific guidelines and recommendations already exist, whereas current knowledge concerning late effects in adult-onset cancer survivors is much less clear. Endocrine sequelae of cancer therapy include functional alterations in hypothalamic-pituitary, thyroid, parathyroid, adrenal, and gonadal regulation as well as bone and metabolic complications. Surgery, radiotherapy, chemotherapy, and immunotherapy all contribute to these sequelae. Following irradiation, endocrine organs such as the thyroid are also at risk for subsequent malignancies. Although diagnosis and management of functional and neoplastic long-term consequences of cancer therapy are comparable to other causes of endocrine disorders, cancer survivors need individually structured follow-up care in specialized surveillance centers to improve care for this rapidly growing group of patients.

Risk of second primary tumors in GIST survivors: A systematic review and meta-analysis

INTRODUCTION

Gastrointestinal stromal tumors (GISTs) are rare mesenchymal tumors arising in the gastrointestinal tract. Second primary tumors (SPTs) have been reported frequently, either synchronously or during follow-up, in patients diagnosed with GISTs.

METHODS

We carried out an electronic search of PubMed, SCOPUS, Web of Science, EMBASE, and the Cochrane Library seeking articles investigating the incidence of SPTs in patients with concomitant GIST. All studies were evaluated for heterogeneity before meta-analysis and for publication bias. Pooled incidence rate was estimated using fixed- and random-effects models. Subsite of SPTs was also investigated.

RESULTS

A total of 32 studies met the inclusion criteria, for a total of 19,627 patients with a diagnosis of GIST. The pooled prevalence of SPTs was 20%, with 14% and 3% being synchronous and metachronous tumors, respectively. We found a risk for several specific cancer sites, in particular gastrointestinal (5%) and genitourinary tract cancers (3%). The most frequently associated malignancies were: colorectal (17%), prostate (14%), gastric (9%), esophageal (5.5%), lung (5.4%), hepato-biliopancreatic (4.7%), breast (4.6%), lymphoma (4.4%), kidney (4.35%), and sarcomas (3.3%). Regression analyses revealed a significant positive association for all SPTs with follow-up and Miettinen risk.

CONCLUSIONS

Our results indicate that 20% of patients with GIST experienced a SPT, primarily synchronously with a diagnosis of GIST. In particular, we observed an excess of incident gastrointestinal tumors. These findings have important implications for both pathologists, who should perform extensive molecular analysis of surgical non-GIST specimens in resected patients, and for oncologists, who should continue to follow up GIST patients.

Review of the possible association between thyroid and breast carcinoma

Background

Thyroid and breast cancer are two of the malignant diseases with highest incidence in females. Based on clinical experience, breast and thyroid cancer often occur metachronously or synchronously. Therefore, thyroid and breast cancer might share some common etiological factors. The relationship between these diseases has attracted substantial attention, and because these two glands are both regulated by the hypothalamic-pituitary axis, such a relationship is not surprising. A study of this relationship will be useful for obtaining a better understanding of the mechanism by which these two malignancies co-occur.

Main body

This study reviewed the progress in research on the roles of iodine intake, folate metabolism, obesity, gonadal hormones, and thyroid hormone in thyroid and breast cancer. These studies evaluating the etiological roles of these factors in linking breast and thyroid cancer might also improve our understanding and identify new therapeutic approaches, such as sodium/iodide symporter-mediated radioiodine therapy and thyroid-stimulating hormone receptor antagonists, for breast cancer. In addition, some specific treatments for each cancer, such as radiotherapy for breast cancer or radioactive iodine therapy for thyroid cancer, might be risk factors for secondary malignances, including breast and thyroid cancer.

Conclusions

Studies of the precise relationship between the co-occurrence of breast and thyroid cancer will certainly improve our understanding of the biological behaviors of these two malignancies and direct evidence-based clinical practice.

Incidence of Second Malignancy in Patients with Papillary Thyroid Cancer from Surveillance, Epidemiology, and End Results 13 Dataset

Increased risk of second primary malignancy (SPM) in papillary thyroid cancer (PTC) has been reported. Here, we present the most updated incidence rates of second primary malignancy from original diagnosis of PTC by using the data from the Surveillance, Epidemiology, and End Results. In this cohort, 3,200 patients developed SPM, a substantially higher number than in the reference population of 2,749 with observed to expected ratio (O/E) of 1.16 (95% CI; 1.12–1.21). Bone and joint cancer had the highest O/E ratio of 4.26 (95% confidence interval [CI] 2.33–7.15) followed by salivary gland (O/E 4.15; 95% CI 2.76–6.0) and acute lymphocytic leukemia (O/E 3.98; 95% CI 2.12–6.8). Mean age at the diagnosis of SPM was 64.4 years old. Interestingly, incidence of colorectal cancer was lower in thyroid cancer survivors compared to general population (large intestine O/E 0.3; 95% CI 0.06–0.88, rectum O/E 0.6; 95% CI 0.41–0.85); however, this was not observed in patients who underwent radiation therapy. The incidence of SPM at all sites was higher during 2000–2012 compared to 1992–1999 (O/E 1.24 versus 1.10). Surprisingly, patients with micropapillary cancer had higher incidence of SPM than counterparts with a larger tumor in radiation group (O/E of 1.40 versus 1.15). O/E of all cancers were higher in males compared to females with O/E of 1.41 versus 1.17 during the period of 2000–2012. Diagnosis of PTC before age 50, especially at age 30–34, was associated with higher incidence of overall SPM (age 30–34; O/E 1.43; 95% CI; 1.19–1.71). Efficient monitoring strategies that include age at the time of thyroid cancer diagnosis, exposure to radiation, gender, and genetic susceptibility may successfully detect SPM earlier in the disease course. This is especially important given the excellent prognosis of the initial thyroid cancer itself.

Secondary Salivary Gland Malignancy in Thyroid Cancer: A United States Population Based Study

Background

There is an increased risk of second primary malignancies with thyroid cancer. However, the risk and characters of secondary salivary gland malignancy (sSGM) in patients with thyroid cancer have not been evaluated before.

Methods

We used the Surveillance Epidemiology and End Results (SEER) 18 registry to identify thyroid cancer patients from 1973 to 2014. We then calculated the risk of sSGM using standardized incidence ratio and excess risk. Separately, all cases of primary salivary gland malignancy (pSGM) diagnosed between 1973 - 2014 were extracted from the SEER 18 registry, and their characteristics compared with sSGM using independent samples t-test for continuous variables and Chi-square tests for categorical variables.

Results

There were a total of 68,339 cases of primary thyroid cancer. Of these, 18 patients developed sSGM with the observed to expected ratio being 3.58 (95% CI: 2.12 to 5.65; P < 0.05) and excess risk being 0.48 per 10,000 population. The incidence of sSGM remained higher between 6 months to 10 years from the time of diagnosis of thyroid carcinoma. The risk of developing sSGM was significantly higher if they were below 60 years of age (O/E: 4.51; 95% CI: 2.33 - 7.88; P < 0.05), were females (O/E: 4.91; 95% CI: 2.80 - 7.97; P < 0.05), were whites (O/E: 3.04; 95% CI: 1.62 - 5.1 9; P < 0.05), had well-differentiated thyroid carcinoma (O/E: 9.70; 95% CI: 3.90 - 19.98; P < 0.05) or were treated with radioactive iodine (O/E: 5.26; 95% CI: 2.72 - 9.19; P < 0.05). While the proportion of females developing sSGM was significantly greater than those developing pSGM (88.9% vs. 44%; P < 0.05), there was no statistical difference between pSGM and sSGM in terms of the age at diagnosis, the proportion of patients diagnosed before 60 years of age, anatomic site of origin or the histological grade of tumor.

Conclusions

Patients with thyroid cancers are at an increased risk of developing sSGM than the general population. This risk is greater if the person is below 60 years of age, female, white, with well-differentiated thyroid carcinoma or is treated with radioactive iodine.

A Rare Case of Synchronous Papillary Microcarcinoma and Metastatic Neuroendocrine Tumor of Unknown Primary

Thyroid papillary microcarcinomas (PMCs) usually follow a very benign clinical course and are rarely metastatic. Any case of PMC presenting with distant metastases without any rising thyroglobulin level should be suspected to have any other primary apart from the thyroid and a meticulous clinical and diagnostic approach should be considered to identify the second primary. We hereby present a case of 52-year-old female treated as PMC with metastatic liver lesion, which was initially thought to be of thyroidal origin. Later, it was diagnosed as a metastatic neuroendocrine tumor of unknown primary.

Characteristics and survival of patients with metachronous or synchronous double primary malignancies: breast and thyroid cancer

BACKGROUND

Clinical experiences suggest that breast cancer (BC) and thyroid cancer (TC) occur metachronously or synchronously in a patient more frequently than it would by chance. This study was conducted to investigate the clinicopathological characteristics and survival of these double primary malignancies.

METHODS

18732 patients with first primary BC and 12877 female patients with first primary TC were performed in this retrospective case-controlled study. The control groups were matched with both age at diagnosis and time of surgery (±2 years). The clinicopathological factors, Overall survival (OS), and HRs were evaluated by SPSS.

RESULTS

There were 91(0.49%) BC patients developed metachronous second primary TC (B-T group), and 117 (0.91%) TC patients developed metachronous second primary BC (T-B group).The expression of estrogen and progesterone receptors, and the value of Ki-67, were significantly higher in the B-T group than control. The median value of thyroid globulin antibody (TGAb) and thyroid peroxidase antibody (TPOAb) were higher in T-B group than control (p <0.05). The duration before second primary cancer was shorter for the B-T group than the T-B group (4.09 years vs. 5.82 years, p<0.001). B-T group patients showed poorer survival than BC only patients (p=0.044).

CONCLUSIONS

In general, the overall risk of the occurrence of a second primary TC or BC elevated highly in patients with BC or TC. Detailed mechanisms need to be studied to explore the association between these two cancers. Early detection and effective prevention for the first primary BC or TC patients are necessities for reducing the incidence of the second primary cancer and improving the OS.

Risk of Hematologic Malignancies After Radioiodine Treatment of Well-Differentiated Thyroid Cancer

Purpose To investigate the risk and outcomes of second hematologic malignancies (SHMs) in a population-based cohort of patients with well-differentiated thyroid cancer (WDTC) treated or not with radioactive iodine (RAI). Methods Patients with WDTC were identified from SEER registries. Competing risk regression analysis was performed to calculate the risks of SHMs that occurred after WDTC treatment and outcomes after SHM development were assessed. Results Of 148,215 patients with WDTC, 53% received surgery alone and 47% received RAI. In total, 783 patients developed an SHM after a median interval of 6.5 years (interquartile range, 3.3 to 11.2 years) from WDTC diagnosis. In multivariable analysis, compared with those undergoing thyroidectomy alone, RAI treatment was associated with an increased early risk of developing acute myeloid leukemia (AML; hazard ratio, 1.79; 95% CI, 1.13 to 2.82; P = .01) and chronic myeloid leukemia (CML; hazard ratio, 3.44; 95% CI, 1.87 to 6.36; P < .001). This increased risk of AML and CML after RAI treatment was seen even in low-risk and intermediate-risk WDTC tumors. Occurrence of AML but not CML in patients with WDTC was associated with shorter median overall survival compared with matched controls (8.0 years v 31.0 years; P = .001). In addition, AML developing after RAI trended toward inferior survival compared with matched controls with de novo AML (median overall survival, 1.2 years v 2.9 years; P = .06). Conclusion Patients with WDTC treated with RAI had an increased early risk of developing AML and CML but no other hematologic malignancies. AML that arises after RAI treatment has a poor prognosis. RAI use in patients with WDTC should be limited to patients with high-risk disease features, and patients with WDTC treated with adjuvant RAI should be monitored for myeloid malignancies as part of cancer surveillance.

Persistent Hematologic Dysfunction after Peptide Receptor Radionuclide Therapy with 177Lu-DOTATATE: Incidence, Course, and Predicting Factors in Patients with Gastroenteropancreatic Neuroendocrine Tumors

Peptide receptor radionuclide therapy (PRRT) may induce long-term toxicity to the bone marrow (BM). The aim of this study was to analyze persistent hematologic dysfunction (PHD) after PRRT with ¹⁷⁷Lu-DOTATATE in patients with gastroenteropancreatic neuroendocrine tumors (GEP NETs). Methods: The incidence and course of PHD were analyzed in 274 GEP NET patients from a group of 367 patients with somatostatin receptor-positive tumors. PHD was defined as diagnosis of myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), myeloproliferative neoplasm (MPN), MDS/MPN, or otherwise unexplained cytopenia (for >6 mo). Using data from The Netherlands Cancer Registry, the expected number of hematopoietic neoplasms (MDS, AML, MPN, and MDS/MPN) was calculated and adjusted for sex, age, and follow-up period. The following risk factors were assessed: sex, age over 70 y, bone metastasis, prior chemotherapy, prior external-beam radiotherapy, uptake on the [¹¹¹In-DTPA⁰]octreotide scan, tumor load, grade 3-4 hematologic toxicity during treatment, estimated absorbed BM dose, elevated plasma chromogranin A level, baseline blood counts, and renal function. Results: Eleven (4%) of the 274 patients had PHD after treatment with ¹⁷⁷Lu-DOTATATE: 8 patients (2.9%) developed a hematopoietic neoplasm (4 MDS, 1 AML, 1 MPN, and 2 MDS/MPN) and 3 patients (1.1%) developed BM failure characterized by cytopenia and BM aplasia. The median latency period at diagnosis (or first suspicion of a PHD) was 41 mo (range, 15-84 mo). The expected number of hematopoietic neoplasms based on The Netherlands Cancer Registry data was 3.0, resulting in a relative risk of 2.7 (95% confidence interval, 0.7-10.0). No risk factors for PHD could be identified for the GEP NET patients, not even bone metastasis or estimated BM dose. Seven patients with PHD developed anemia in combination with a rise in mean corpuscular volume. Conclusion: The prevalence of PHD after PRRT with ¹⁷⁷Lu-DOTATATE was 4% in our patient population. The median time at which PHD developed was 41 mo after the first PRRT cycle. The relative risk for developing a hematopoietic neoplasm was 2.7. No risk factors were found for the development of PHD in GEP NET patients.